Investigation of the transport properties of ions confined in nanoporous carbon is generally difficult because of the stochastic nature and distribution of multiscale complex and imperfect pore structures within the bulk material. We demonstrate a combined approach of experiment and simulation to describe the structure of complex layered graphene-based membranes, which allows their use as a unique porous platform to gain unprecedented insights into nanoconfined transport phenomena across the entire sub–10-nm scales. By correlation of experimental results with simulation of concentration-driven ion diffusion through the cascading layered graphene structure with sub–10-nm tuneable interlayer spacing, we are able to construct a robust, representative structural model that allows the establishment of a quantitative relationship among the nanoconfined ion transport properties in relation to the complex nanoporous structure of the layered membrane. This correlation reveals the remarkable effect of the structural imperfections of the membranes on ion transport and particularly the scaling behaviors of both diffusive and electrokinetic ion transport in graphene-based cascading nanochannels as a function of channel size from 10 nm down to subnanometer. Our analysis shows that the range of ion transport effects previously observed in simple one-dimensional nanofluidic systems will translate themselves into bulk, complex nanoslit porous systems in a very different manner, and the complex cascading porous circuities can enable new transport phenomena that are unattainable in simple fluidic systems.

报告人简介：

Chi Cheng received his Ph.D. in Materials Science and Engineering from Monash University in 2014, and became a Research Fellow at the Monash Centre for Atomically Thin Materials, then a Research Chemist at DuluxGroup Ltd. in 2016. He was named the Australian Endeavour Fellow the same year and will visit Massachusetts Institute of Technology in 2017. His main research interest lies in understanding and control of the mass transport in materials engineering and its implications for energy, separation, controlled-release and signalling. He has authored over 15 publications including one in Science (2nd author), one in Science Advances (1st authors), two in Advanced Materials (1st author). His research has been cited for 1077 times and has a h-index of 9.